#pragma once

////////////////////////////////////////////
//二叉树类型定义

template <typename E>
struct BiTNode
{
    E data;
    BiTNode *lchild,*rchild;
};

template <typename E>
using BiTree = BiTNode <E>*;

////////////////////////////////////
//二叉树基本操作

///先序遍历二叉树 Preorder (T,visit)
template <typename E, typename F>
void Preorder(BiTree<E> T, F visit)
{
    if (T){
        visit(T->data);
        Preorder(T->lchild,visit);
        Preorder(T->rchild,visit);
    }
}

///中序遍历二叉树 Preorder(T,visit)
template <typename E, typename F>
void Inorder(BiTree<E> T,F visit)
{
    if (T){
        Inorder(T->lchild,visit);
        visit(T->data);
        Inorder(T->rchild,visit);        
    }
}

///后序遍历二叉树 Postorder(T,visit)
template <typename E, typename F>
void Postorder (BiTree <E> T, F visit )
{
    if (T){
        Postorder(T->lchild,visit);
        Postorder(T->rchild,visit);
        visit(T->data);
    }
}

///求二叉树结点数 NodeCount(T)
template <typename E>
int NodeCount(BiTree <E> T)
{
    if (T == nullptr )
        return 0;
    auto L = NodeCount(T->lchild);
    auto R = NodeCount(T->rchild);
    return L + R + 1;
}

///求二叉树叶子结点数 LeafCount(T)
template <typename E>
int LeafCount (BiTree <E> T)
{
    if (T == nullptr)
        return 0;
    if (T->lchild == nullptr && T->rchild == nullptr )
        return 1;
    auto L = LeafCount(T->lchild);
    auto R = LeafCount(T->rchild);
    return L + R;
}



///求二叉树深度 Deth(T)
template <typename E>
int Depth(BiTree<E> T)
{
    if (T == nullptr )
        return 0;
    auto L = Depth(T->lchild);
    auto R = Depth(T->rchild);
    return L > R ? L + 1 : R + 1;    
}

#include <iostream>
using std::cout;
using std::endl;

///打印二叉树
template <typename E>
void Print (BiTree <E> T, char prefix = '$', int level = 0 )
{
    if (T) {
        Print (T->rchild, '/',level + 1 );
        for (int i = 0; i < level; ++i) cout << "  ";
         cout << prefix << ' ' << T->data << endl;
         Print (T->lchild, '\\', level + 1); 
    }
}

#include <iostream>
using std::cin;
using std::noskipws;

///建立二叉树 CreateBinaryTree()
BiTree<char> CreateBinaryTree()
{
    char c;
    cin >> noskipws >> c;
    if  (c == ' ') 
        return nullptr;
    else {
    auto T = new BiTNode <char>{c, nullptr, nullptr};
    T->lchild = CreateBinaryTree(); 
    T->rchild = CreateBinaryTree(); 
    return T;
    }
} 
/// 销毁二叉树 Destroy (&T)
template  < typename E>
void Destroy (BiTree <E> &T)
{
    if (T) {
        Destroy (T->lchild);
        Destroy (T->rchild);
        delete T;
        T = nullptr;
    }
}

///////////////////////////////
//二叉排序树基本操作

/// 二叉排序树查找算法 SearchBST(T,e)
template <typename E>
BiTree<E> SearchBST(BiTree<E> T,E e)
{
    if (!T || T->data == e)
        return T;
    else if (e < T->data)
        return SearchBST(T->lchild, e);
    else
        return SearchBST(T->rchild, e);
}

/// 二叉树排序树找最小 FindMinBST(T)
template <typename E>
BiTree <E> FindMinBST(BiTree<E> T)
{
    if (T)
        while (T->lchild)
            T = T->lchild;
    return T;
}

///二叉排序树找最大 FindMaxBST(T)
template <typename E>
BiTree <E> FindMaxBST(BiTree<E> T)
{
    if (T)
        while (T->rchild)
            T = T->rchild;
    return T;
}

///二叉排序树插入 InsertBST(&T,e)
template <typename E>
void InsertBST (BiTree <E> &T,E e)
{
    if (T == nullptr)
        T = new BiTNode<E>{e, nullptr, nullptr};
    else if (e < T->data)
        InsertBST(T->lchild,e);
    else if (e > T->data )
        InsertBST(T->rchild,e);
    else 
        ;
}


///二叉排序树删除 DeleteBST(&T ,e)
template <typename E>
void DeleteBST(BiTree<E> &T, E e)
{
    if (T == nullptr) return;
    else if (e < T->data)
        DeleteBST (T->lchild,e);
    else if (e > T->data)
        DeleteBST (T->rchild,e);
    else{// T->data == e
        if (T->lchild && T->rchild){// T 有两个子树
            T->data = FindMaxBST(T->lchild)->data;
            DeleteBST(T->lchild,T->data);
        }else {// T 至多有一个子树
            auto oldNode = T;
            T = T->lchild ? T->lchild : T->rchild;
            delete oldNode; 
        }
    }
}
